Well the biggest difference I can see is that a microcontroller can do everything a pc can, but on a small scale. A microprocessor on its own is not very good. The processor does have internal memory, but deffinatly not enough to hold a program.

I'm not too sure about the pricings, because comparative processing speed of the microcontroller vs the processor, I think the processor will be cheaper.

As for uses, the microcontroller can do just about any basic task, but the processor can only really number crunch as there are no general inputs/outputs.

sorry to move slightly off topic, but is it possible to run a program just using a processor as they have a very small ammount of memory?

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As far as the microprocessors that have dealt with are concerned, they all tended to assume that the first instruction was at a memory location that was outside the device itself.

It seems like the only storage that a microprocessor has are registers that are used to hold data temporarily. I can't imagine how one could do anything useful with them.

I did see an interesting circuit once where someone had arranged to use pullups and pull-down resistors on the 8-bit data bus to implement a permanent NOP instruction so that the address bus simply acted like a free-running 16-bit binary counter.

As far as the microprocessors that have dealt with are concerned, they all tended to assume that the first instruction was at a memory location that was outside the device itself.

It seems like the only storage that a microprocessor has are registers that are used to hold data temporarily. I can't imagine how one could do anything useful with them.

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Hi hgmjr,

This is pretty much my take. I was assuming in my earlier assessment that the first instruction was residing in the processor registers and that we can abstract from the problems of getting data and instructions into and out of the registers. Some processors are considered to have level-1/2 cache which is a smaller and faster implementation of memory, but then we are down to interpretations or specific architectures.

The reality is that microprocessors are design to take advantage of the full memory heirachy and divergence from this inherently poses problems.

microprocessor contain no RAM,no ROM ,and no I\O ports on the chip itself.for this reason ,they are commonly known as general purposed microprocessors.a microcontroller has microprocessor in addition to RAM,ROM and I|O devices in a single chip.